Thermal imaging cameras are excellent tools for night vision.
They detect thermal radiation and do not need a source of illumination.
Normally grey scale in nature: black objects are cold, white objects are hot and the depth of grey indicates variations between the two.
Some thermal cameras, however, add color to images to help users identify objects at different temperatures
Cup Filled With Hot Water
An image generated from a Thermal Imaging Camera. Note the persons skin (as a heat source) is shown as ‘white hot’ whilst the sea (which is cold) is shown as black.
They produce an image in the darkest of nights and can see through light fog, rain and smoke.